Various structures of superconducting power transmission cable have heretofore been proposed. Ease of laying working and improvements in heat invasion countermeasures has been demanded. For further information on the superconducting cables, following patent specifications 1 and 2 are referenced. For information on an current terminal having a thermoelectric transducer element, patent document 3 is referred to.    [Patent Document 1] JP Patent Kokai Publication P2003-333746A    [Patent Document 2] JP Patent Kokai Publication H10-112407A    [Patent Document 3] JP Patent Kokai Publication P2003-217735A